It’s important to hope for the best, but plan for the worst. If you’re like most people, you’re already behind on saving for retirement–even if you’ve been careful to try and stay on track. This is because most people don’t take rising costs into account when they for retirement, or they don’t place enough importance on this factor.

There are several major factors at play with regard to rising costs as you enter retirement. One is inflation, which in the United States will erode your spending power by roughly 2% to 4% per year on average. Another is an increase in your health-care costs due to the natural complications of aging. And yet another is: You know all those retirement plans you have? They’re darn expensive.

Finally, if you’re more than 5 years away from retirement, you should probably assume that Social Security isn’t going to help you. That isn’t to say that the system is definitely going to crumble, but the fund is currently being depleted much faster than it’s being added to. Therefore, you’ll be best prepared for the worst if you assume it won’t exist while you plan out your savings.

There are many great resources available on the web to find useful investing tips for fueling your retirement fund, and you should certainly check them out to come up with a solid investment plan. But making the right choices as to where you put your money can only help so much; just as important, you’ll need to make sure you save enough in the first place to retire comfortably.